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Apt Holman Preamplifier Review (vintage Audio)

I have (finally) acquired an APT/Holman preamp from a forum member, and it will going to QuirkAudio for refurbishing soon.

What I did not get is the vaunted user manual. Is that available online? Anyone have a scan they could send me? The "service manual" linked a few posts back is a dead link.

Rick "happy Thanksgiving!" Denney
Yep, I tried to bring my copy onto here but it's too large a file.
Sorry
EJ3
 
It's 10.3MB. Probably too big for ASR?

@rdenney if you want a copy, send me a PM with a proper email address.

I sent that to you but now no need. I forgot I am already signed up with Hifi Engine—it’s been a while since I needed a manual and didn’t even think of it until Don and MAB mentioned it—I was working backwards through responses. I have both manuals now.

Rick “thanks, all” Denney
 
They never would unfortunately. The feature set is pretty much normal to us older guys, but it would be a tough sell to people these days.

No need for bi-directional tape dubbing or alternate tape monitoring (no three heads decks to worry about). Tuner? Who uses one these days? Two turntables?- most people have none. And no hipster is going to waste time with measuring responses with different cartridge loading like we did.

The Holman's performance is good, not excellent and certainly not state of the art in the late 1970s, letalone now. But it is riddled with a cascade of circuit elements as it was clearly designed as individual optimised components, not as a holistic preamplifier from end to end. It's circuit design is reminiscent of an old skool tube preamp, with more coupling capacitors than I have ever seen from source to output in one product. No wonder its low end repsonse is as poor as it is.

Even in the most direct route, we have nine (9) coupling caps from phono to line outs.

The phono overload is very disappointing on this Holman, it's rated at over 100mV and we see a 1kHz overload at a paltry 80mV. Sure 100mV can be achieved at 1%, but there were plenty of preamplifiers out there with 300-400mV overloads at the time.
The frequency response should be ruler flat, but it just cannot be with the design. We see rolloff commencing at 200Hz.

I like the TI TL-072 Jfet opamps, even if they are run right on their max voltage edge, they are a classic and it's pretty amazing to see the entire preamp is run from a single pair of regulators uA-7818/7918 (+/-18V). No fancy individual channel discrete regulated supplies here- it's about as cheap and simple as you could get. And yet it works pretty well.

I really wish someone in the US close to Amir could send him the old Japanese classics of the same era, such as the Yamaha C-2/2a/2x, Denon PRA-1000/2000/3000, Kenwood LO-7c/7cii, Sony TAE-86/86B, Technics SU-9070/9200/9600 etc. Surely some of you guys have some in your collections?
Hi,

I Have the Yamaha C-2x , it looks and sounds amazing (or rather doesn't sound, because it sounds utterly neutral to me), and I would love to have it measured but i'm not going to sent it halfway across the planet though;)
 
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